Thread: Overlapping memory addresses in a struct :/

I have a binary tree and a struct with three tree pointers and a void pointer for the key of the node.When trying to insert a node,even though the key gets the value that it is expected,then when i set the tree pointers to NULL,the left pointer seems to overwrite the void pointer and as a result i get a key equal to zero always!

The insertion function

Code:

Treeptr addtree(Treeptr p, void* v ,int sizeOfType,int (*compare)
     ( void* arg1, void* arg2))
                                     /* Insert value v into tree p */
{
  Treeptr y = NULL;
  Treeptr x = p;
                                    /* Allocate space for new node */
  Treeptr z = malloc(sizeof(Treeptr));
  printf("The value inside the function %d\n",*(int*)v);
  z->value = malloc(sizeOfType);      /* Allocate memory for value */
  memcpy( z->value , v , sizeOfType );               /* Copy value */
  printf("The value of node BEFORE setting the pointers to null %d\n",*(int*)z->value);
  z->left = NULL;
  z->right = NULL;
  z->parent = NULL;
  printf("The value of node AFTER setting the pointers to null %d\n",*(int*)z->value);
  while(x != NULL) {
     y = x;
     if( compare(z->value,x->value) == -1 )
        x = x->left;
     else
        x = x->right;
  }
  z->parent = y;
  if(y == NULL) {
     p = z;
  }
  else if( compare(z->value,y->value) == -1 ) {
     y->left = z;
  }
  else {
     y->right = z;
  }
  return p;
}

My struct

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct tnode *Treeptr;

typedef struct tnode {
  Treeptr left;
  Treeptr parent;
  Treeptr right;
  void* value;
} Treenode;

Treeptr addtree(Treeptr p, void* v ,int sizeOfType,int (*compare)
     ( void* arg1, void* arg2));
void nodesGeneric(Treeptr,void(*)(void*));
Treeptr minnode(Treeptr p);
Treeptr successor(Treeptr x);
Treeptr treesearch(Treeptr p, void* v);
Treeptr deletenode(Treeptr p ,void* v);

The main

Code:

int main(void)
{ Treeptr p;
  char answer;
  void* v;
  int value,n,i;
  p = NULL;                               /* Initialize binary tree */

  printf("Please insert number of nodes of the tree\n");
  scanf("%d",&n);
  if(n < 1)
  {
    printf("\nValue less than one inserted.Exiting...\n");
    return -1;
  }
  printf("Please insert nodes of tree.\n");
  for( i = 0 ; i < n ; i++ ) {
    scanf("%d", &value);                  /* Read values from input */
                v = &value;                /* and insert them into the tree */
    p = addtree(p, v , sizeof(int) , int_sorter);
  }
  .....
  return 0;
}

I tried to play around with the position of the pointers,where i set them to null and where they are placed inside the struct,but again i had the same problem.Actually once i got a segmentation fault...What is the problem?